又硬又粗进去好爽A片春色视频,大量国内自拍AV手机观看,99re这里只有国产中文精品国产精品,人妻无码AV一区二区三区

We all have a deep understanding of the hot summer. Pig breeding must also use pig breeding equipment to cool down the pigsty. There are two ways to cool down the pigsty: external cooling and internal cooling. However, there are some differences between the two ways. Let's introduce them to you.
External cooling is to reduce the temperature of the pig environment, internal cooling is to reduce the temperature of the pig body; compared with the two effects, the effect of internal cooling is better than external cooling. The reason is that internal cooling can release extra heat from the body. For pigs, there are two ways to cool down inside: one is to collect or drink water. The feed and drinking water to cool down will turn into high-temperature dung and urine, which will take a lot of heat away; to make pigs drink more water, in addition to lowering the water temperature, we should also pay attention to the increase of salt concentration in the feed in summer. The second is to change the dry air into moist air, and take away the body heat through the evaporation of water in the body, which is the most easily ignored and very important place for us. It should be noted that the difference between the concentration of water vapor in the inhaled and exhaled gas is different. If the concentration of water vapor in the inhaled and exhaled gas is the same, there will be no cooling effect; if the concentration difference between the two is large, the cooling effect will be very good; to ensure that pigs inhale dry air is an important condition for internal cooling, so we often encounter high temperature but low humidity, mother Pigs do not die of heat; the temperature is not very high, but when the humidity is high, sows die of heat; the main reason is that the cooling does not work.